What is HIV?
Definition
The Human Immunodeficiency Virus (HIV) is a retrovirus (a virus which uses the body's own cells to reproduce itself) that attacks the human body's immune system and causes the Acquired Immune Deficiency Syndrome (AIDS).
The first cases of AIDS
The exact origins of HIV are unclear. In the developed world, doctors first noticed it in 1981 when an increasing number of homosexual men were presenting with specific opportunistic diseases, including Kaposi's Sarcoma (KS) and pneumocystis carinii pneumonia (PCP).
Read more: Kaposi's Sarcoma in homosexual men: A report of eight cases. The Lancet, 1982.
At the time very little was known about this new disease. As it initially seemed to be isolated to homosexual men, it was first called GRID - Gay Related Immune Deficiency Syndrome. This soon changed when when cases of this new mystery disease was noticed amongst hemophiliacs, intravenous drug users and Haitians. The name AIDS (Acquired Immunodeficiency Syndrome) was first used on 27 July 1982 at a meeting in Washington D. C.
Cases of AIDS were noted much earlier in Africa, where it was first known as "slims disease". It is now known that the HI virus is a descendant from a Simian Immunodeficiency Virus that affects monkeys. The virus is thought to have crossed over to humans in Africa as early as 1884.
The virus responsible for AIDS was first discovered in 1983 at the Institute Pasteur in Paris, lead by Luc Montagnier. As it was first referred to a as lymphadenopathy associated virus, HIV first went by the acronym LAV.
In 1984 Dr. Robert Gallo from the National Cancer Institute in the US announced he had isolated the cause of AIDS. What he called the human T-cell leukemia/lymphoma virus III (HTCL-III), was in fact the same as the French LAV. The virus was later renamed HIV-1.
A second HI virus was identified two years later and became known as HIV-2.
There are two types of HIV: HIV-1 and HIV-2. HIV-1 is predominant worldwide and mutates very easily. HIV-2 was identified in 1986 and is prevalent in West African countries. There are many similarities between HIV-1 and HIV-2 (e.g. both are transmitted in the same way, both are associated with similar opportunistic infections and AIDS), but in persons infected with HIV-2, immunodeficiency develops more slowly and the virus is less infectious.
Strains of HIV are classified into four main groups. More than 90% of HIV-1 infections belong to HIV-1 group M. A number of subtypes or clades again differentiate between variants of each group.
The Mail & Guardian reports that doctors and HIV-positive… Read more